<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
  <style>
    .content{width: 100px; height: 40px; line-height: 40px; background: #999; text-align: center;} .content1 {
      width: 200px;
      height: 100px;
      background: #999;
      position: relative;
      margin-top: 10px;
    }

    .content1 p {
      position: absolute;
      left: 50%;
    }
    .content1 p>span{
        border-top:4px solid;
        border-left: 4px solid transparent;
        border-right:4px solid transparent;
    }
  </style>
</head>
<body>

<div class="content1">
  <p>
      hello world<span></span>
      <span></span>
  </p>
</div>
<script>

  var trim1 = function (str) {
    return str.split(" ")[1];
  }

  // /^(([a-z0-9]+-)?[a-z0-9]+\.)+[a-z]{2,6}$/.test("ww-dd.w3333-dd-d.com");//域名匹配正则
</script>
</body>
</html>